Sprinkler head



United States Patent Ofitice 2,845,304 Patented J uly' 29, 1 958SPRINKLER HEAD Gerard N. Stelma, Edwin J. Krook, and Louis R. King,Grand Rapids, Mich, assignors to Dexter Industries, Inc., Grand Rapids,Mich.

Application July 9, 1956, SerialNo. 596,733

4 Claims. (Cl-29120) This invention relates to the construction ofsprinkler heads, and has been developed primarily for irrigation systemsinvolving a series of the units connected to an underground supply pipe.The orifice, or discharge outlet, is preferably about at ground level,and the unit does not project to a height that would interfere with alawn mower. To operate satisfactorily, the units must create a gooddispersion of the water in contrast to merely wetting a small spot orring. Simplicity and reliability requirements prevent the use of movingparts, and the necessary break-up of the supply flow into a fine spraymust be accomplished. by the relationship of components which are fixedwith respect to each other except for adjustment.

The use of a series of units connected to a supply pipe of considerablelength requires that the units be adjustable to compensate for variouspressures along the. line, so that all the units in the series will havea similar delivery. These variations of pressure should be accommodatedby the unit at a given delivery rate without excessive distortion of thespray pattern or drop size.

Devices of this type utilizing an adjustable valve system are not new.Applicants have, however, discovered a relationship between thecomponents which results in.

excellent performance, and which involves a valving action at a pointremote from the orifice (as far as the fluid. dynamics of the device isconcerned). Preferably, the valve unit itself imparts a rotation to thestream by causing it to pass through slots disposed at an angle to theaxis of the unit. The slots themselves provide passages ofquickly-expanding cross section along the flow path, Which seems to havea beneficial effect on the dropsize of the spray. The dimensions of theslots, of the equalization chamber between the slots and the orifice, ofthe orifice, and the orientation of the slots all appear to be ofconsiderable importanceat least the relationship of each with respect tothe others. While it has not been possible at this time to determine aformula establishing the relationship of all the elements withprecision, a set of dimensions will be disclosed herein for a modelwhich performs excellently.

The proper functioning of the unit not only requires that the valvingaction be adjustable; but that once the adjustment is made, it should bemaintained. In the preferred form of the invention, the adjustment ofthe valve. with respect to the valve seat is accomplished by providing athreaded engagement between the shank of the valve and a member fixedwith respect to the body. It is thereforeimportant that a certainresistance to rotation be provided so that the valve member will notgradually displace itself from the adjusted position as a result of thetorque derived from rotating the spray. It is also desirable that theshank of the valve should be maintained as closely as possible incoaxial relationship with the conduit which it controls. Both of theserequirements are met, in the preferred form of the invention, by theprovision of an axially-extending diametral slot in the threaded portionof the valve shank. This slot is filled-preferably with aforced-fit-with a readilydeformable material of the type commonlyreferred to as plastic. This material serves two functions. The first ofthese is simply that the presence of the forced relationship in the slottends to expand the threaded, shank and force it more tightly intoengagement with the internal threads with which it cooperates. It isimportant to note that the expansion in one direction actually serves:the purpose of stabilizing the axis of the devicein all directions as aresult, of the tight engagement. of. the threads. If. an un-threadedengagement. were involved, expansion would have to take place onperpendicular axes, but the presence of the threads removes thisnecessity. The added function of the deformable insert material: resultsfrom the fact that it is preferably shaped tov extendjout into aposition of interference with. the threads of. the internally-threadedmember. As the valve isforceahly rotated into adjusted position, thethreads of the inter. nally-threaded member force their way into thedeformable material, and a solid pre-determined resistance to rotationresults.

The several features of the. invention will be analyzed in detailthrough a discussion of. the particular embodiments illustrated in theaccompanying drawing. In the drawing:

Figure 1 presents a sectional elevation along the axis of the completelyassembled device;

Figure 2 presents a section taken on the plane 2--2 of Figure 1.

Figure 3 presents a section on a somewhat enlarged scale of the capcontaining the orifice.

Figure 4 presents a view in elevation on an enlarged" scale of the valvemember.

Figure 5 presents a top view of the valve member, on' the same scale asthat of Figure 4.

Figure 6 presents a view from the bottom of'the valve member, also onthe same scale as that of Figure 4.

Referring to the drawing, the illustrated sprinkler head unit includesthe body member generally'indicated' at 10' which has anoutwardly-flared funnel-shaped upper portion 11, the unit ordinarilybeing installed with this portion of the device approximately at groundlevel. The axis 12 of the unit is usually vertical. A central here,which is coaxial with axis 12, receives the lower end of the cap 13,preferably in a fairly close fit. When fully assembled, the cap 13 maybe considered as fixed with respect to the body member 10 either throughthe use of a forced-fit, through the application of soldier, or throughthe upsetting of the lip 14 in a manner as to generate a constrictingaction inwardly against the cap 13. The hole 15 in the top of the cap 13provides a discharge orifice for the spray.

A conduit through the body member is provided by the coaxial passagesformed by' the coupling portion16, the bore 17, the bore 18, andcommunicating passages around the insert 25. A shoulder 19extendsbetween the bore 18 and the bore which receives the cap 13.. Theinside diameter of the cap. 13 may also be consideredas. the equivalentof a bore which is a continuation of the coaxial group. previouslyreferredto.

A valve member generally indicated at- 20 has ahead.

i serted with a pressed fit into the bore 17, which binds the insert 25at its corners, leaving open passages between the insert and the bore 17communicating between the bore 17 and the coupling portion 16. Theinsert, therefore, occupies less than the entirety of the cross-sectionof the bore in which it is positioned, exclusive of the centralinternally-threaded opening engaged by the shank 24.

The head 21 of the valve member, in the illustrated modification of theinvention, is provided with a series of preferably threeperipherally-spaced slots 26, 27, and 28. Four has also been found towork satisfactorily. Each of these slots is preferably formed by theaction of a milling cutter which engages the head 21 in such a fashionthat each slot at the top of the valve member is bisected by a radius tothe axis 12 of the unit, the sides 29 of the slot being in parallelplanes perpendicular to the base of the slot. A rounded cutter giving aslot which is arcuate in cross-section can be used in place of theillustrated form. The angle of the slot indicated at 30 in Figure 4 withrespect to the axis 12 causes a rotary motion to be imparted to the flowof water passing through the slots, which is largely responsible for thelateral projection of the spray. In the illustrated modification, thebase or bottom of the slots (as indicated at 31 in Figure 4) is machinedin a plane substantially parallel to the axis 12. The result of thegeometrical relationships arising from this manner of forming the slots26, 27, and 28 (which applies to an alternative cutter shape as well),is to create a smaller cross-section to the slots at the conical surface22 than at the discharge end adjacent the top surface 32 of the head.This variation in cross-section, in view of the relatively high velocityof flow and the turbulence created by the fairly sharp edges of theslot, seems to create a very desirable tendency to reduce the drop-sizeof the spray. Figures 5 and 6 best illustrate the formation of the slotsand the change of cross-section that takes place. The periphery 33 ofthe top fitswithin the inside diameter of the cap 13 with a minimum ofclearance, resulting in forcing the entire flow of the device throughthe slots 26, 27, and 28.

While the quantity of flow through the unit is principally determined bythe distance between the conical surface 22 of the valve unit 20 and thebeveled seat 34 at the juncture of the shoulder 19 and the bore 18, theeffect on the flow of water caused by the valving action itself may beconsidered as isolated from the discharge orifice 15. The entire flowpasses from the valving area through the slots 26, 27, and 28, and theequalization chamber 35 provided between the top surface 32 of the valveand the under side of the cap 13 is substantial enough in height so thatthe variations in height of the valve member to secure the necessaryflow adjustment do not result in sufiicient altering of thecharacteristics of the equalization chamber to cause any appreciabledifference in the spray characteristics. Flow in the equalizationchamber 35 rotates at a rapid rate as a result of the emergence of theflow from the inclined slots 26, 27, and 28; and on emerging from thedischarge orifice, the rotation imparts a sufficient centrifugal forceto generate the desirable dispersion of the spray in a lateraldirection.

The dimensional relationships of the various components seem to berather important in the over-all performance of the unit. Since it hasnot been possible to determine with precision a formula which willpositively establish the relationship of the various dimensions,including the allowable variations from the preferred dimensions, a setof dimensions will be disclosed herein which have been found to create avery satisfactory unit. It is intended that this disclosure of specificdimensions will illustrate approximately the proportional relationshipsinvolved, and is not to be understood as the only set of dimensions thatwill form an operative device. Using a diameter of approximately /2 inchfor the bore 17, and inch for the bore 18, an inside diameter ofapproximately inch (indicated at 36 Figure 3) for the cap has been foundsatisfactory. The inside height of the cap 13 (indicated at 37 Figure 3)is preferably approximately /8 inch. The thickness of the peripheraledge 33 of the head 21 is preferably approximately inch (this dimensionbeing indicated at 38 in Figure 4). The cone angle of the surface 22(indicated at 39) is preferably approximately120 degrees. With theseproportions, the discharge orifice diameter indicated at 40 in Figure 3should be approximately 7 inch. The thickness of the material at the topof the cap 13 (through which the discharge orifice 15 extends) isapproximately inch.

With regard to the slots in the head of the valve member, a slot depth(indicated at 41 in Figure 5) of inch appears to be adequate. The widthof the slot (indicated at 42 Figure 4) in a direction perpendicular tothe direo tion of flow through the slot has also been found to beadequate at inch. The angle 30 of these slots with respect to the axis12 appears to be most effective when established at approximatelydegrees.

In order to stabilize the valve members 20, both with respect to thecoaxial relationship to the internally-fitted insert 25 and also againstshifting of its rotary adjustment, the threaded shank 24 is slotted at43 with a diametral slot extending from the lower end of the Shankupward to a sufficient extent so that the slotted area is normally atall times within the area encountering the threaded insert 25. A stripof plastic material (indicated at 44) is preferably forced intoengagement with the slot 43, p or the opposite sides of the shank 20 maybe sprung f together after the slot 43 has been machined. In any event,the plastic material should be fairly well clamped in engagement withthe shank 24 to maintain its position with respect thereto. It ispreferable, however, that the dimensions of the plastic piece 44 be suchas to normally spread the opposite sides of the shank into a more secureengagement with the internally threaded member 25 than would be the caseif the shank were left unslotted. This arrangement results in drivingthe threads on the opposite sides of the shank into firm relationshipwith the internal threads, which stabilizes the valve memher in itscoaxial relationship with the unit. When the threads are forced intotight engagement, this action results not only in stabilizing the valvein a plane perpen dicular to the slot 43, but also against displacementin the plane of the slot itself. This action results from the fact thata V-shaped member, when driven into solid engagement with asimilarly-shaped groove cannot be rotated about an axis parallel to thedirection of the application of pressure.

In addition to this function, it is preferable that the plastic member44 extend radially outward on the opposite sides a sufficient amount toreach a position of interference with the internal threads of the insert25. Since the plastic is relatively more easily deformable than thebrass of which the shank 24 and the insert 25 are usually formed, therotation of the valve member into engagement with the insert 25 willcause the threads of the insert 25 to create threads in the exposedportions of the plastic strip 44. Since material is forcibly displacedduring this operation, a firm pre-determined resistance to rotationresults which maintains the adjusted position of the valve member. Itmay also be noted that, if a high degree of compression exists betweenthe slot 43 and the material of the plastic strip 44, such compressionwill tend to cause the plastic member to move outwardly into more closeengagement with the threads. It is well known that plastic tends to flowto a very limited degree under the application of continuous pressure.

The particular embodiments of the present invention which have beenillustrated and discussed herein are for illustrative purposes only andare not to be considered as a limitation upon the scope of the appendedclaims.

In these claims, it is our intent to claim the entire i11- ventiondisclosed here, except as we are limited by the prior art.

We claim:

1. A sprinkler head, comprising: a body member having an outwardlyflared portion at the normally upper most end thereof, said body memberhaving a bore coaxial with said flared portion, a conduit communicatingwith said bore and extending through said body portion and having asmaller diameter from that of said bore and also having an annularshoulder extending between said conduit and said bore; a member disposedwithin said conduit and fixed with respect thereto, said member having athreaded hole coaxial with said bore, and said member occupying lessthan the full cross-section of said conduit at said threaded memberexclusively of said threaded hole; a valve member having a threadedshank engaging said threaded hole, and including a head provided with aconical surface adjacent said shank having a diameter greater than thatof said conduit at said shoulder, and having a driving recess in theside opposite from said shank, said head having a series of slots spacedabout the periphery thereof and inclined to the axis of said shank byapproximately forty-five degrees, said slots increasing incross-sectional area proceeding from the side of said head adjacent saidshank; and means forming a chamber closely surrounding said head andcommunicating with said conduit, said chamber being fixed with respectto said body member and having an orifice coaxial with said conduit.

2. A sprinkler head, comprising: a body member, said body member havinga bore, a conduit communicating with said bore and extending throughsaidbody portion and having a smaller diameter from that of said boreand also having an annular shoulder extending between said conduit andsaid bore; a member disposed within said conduit and fixed with respectthereto, said member having a threaded hole coaxial with said bore, andsaid member occupying less than the full cross-section of said conduitat said member exclusively of said threaded hole; a valve member havinga threaded shank engaging said threaded hole, and including a headprovided with a conical surface adjacent said shank having a diametergreater than that of said conduit at said shoulder, and having a drivingrecess in the side opposite from said shank, said head having a seriesof slots spaced about the periphery thereof and inclined to the axis ofsaid shank by approximately forty-five degrees, the base of said slotsextending along a plane substantially parallel to the axis of said valvemember, said slots increasing in crosssectional area proceeding from theside of said head adjacent said shank; and means forming a chamberclosely surrounding said head and communicating with said conduit, saidchamber being fixed with respect to said body member and having anorifice coaxial with said conduit.

3. A sprinkler head, comprising: a body member, said body memberhaving'a bore, a conduit communicating with said bore and extendingthrough said body portion and having a smaller diameter from that ofsaid bore and also having an annular shoulder extending between saidconduit and said bore; a member disposed Within said conduit and fixedwith respect thereto, said member having a threaded hole coaxial withsaid bore, and said threaded member occupying less than the fullcrosssection of said conduit at said member exclusively of said threadedhole; a valve member having a threaded shank engaging said threadedhole, and including a head having a diameter greater than that of saidconduit at said shoulder, and having a driving recess in the sideopposite from said shank, said head having a series of slots spacedabout the periphery thereof and inclined to the axis of said shank, saidslots increasing in crosssectional area proceeding from the side of saidhead adjacent said shank; and means forming a chamber closelysurrounding said head and communicating with said conduit, said chamberbeing fixed with respect to said body member and having an orificecoaxial with said conduit.

4. A sprinkler head, comprising: a body member, said body member havinga bore, a conduit communicating with said bore and extending throughsaid body portion and having a smaller diameter from that of said boreand also having an annular shoulder extending between said conduit andsaid bore; a member disposed within said conduit and fixed with respectthereto, said member having a threaded hole coaxial with said bore, andsaid threaded member occupying less than the full cross-section of saidconduit at said member exclusively of said threaded hole; a valve memberhaving a threaded shank engaging said threaded hole, and including ahead having a diameter greater than that of said conduit at saidshoulder, and having a driving recess in the side opposite from saidshank, said head having a series of slots spaced about the peripherythereof and inclined to the axis of said shank; and means forming achamber closely surrounding said head and communicating with saidconduit, said chamber being fixed with respect to said body member andhaving an orifice coaxial with said conduit.

References Cited in the file of this patent UNITED STATES PATENTS1,438,097 Cole Dec. 5, 1922 1,438,104 Farrell Dec. 5, 1922 1,724,662Johnson Aug. 13, 1929 2,083,282 Thompson June 8, 1937 2,709,623 GlynnMay 31, 1955 FOREIGN PATENTS 14,100 Great Britain Dec. 2, 1909

